Well, interesting question.
First, I'm not sure if any of these guys will be considered employees - I don't think the businesses will want them as employees. Health insurance, workers compensation, 401k, etc. I suppose they could be considered "part-time" employees which may get the employer off the hook for some of that.
I think they will mostly be Independent Contractors - their job won't be football, it will be "marketing" or "public relations". Remember they are not being paid to play football (wink), they are being paid for their NIL.
Some clever accountant or lawyer may try to claim that they have "sold their NIL", which is an intangible asset and should be treated as a capital gain and not subject to self-employment tax.
I'm not buying it, and I don't think the IRS will either. That doesn't mean it won't get litigated.
I also don't think they will be employees of the school. If they are it would be a tax disaster. The scholarship would be taxable and the athletic program would likely lose their tax exempt status.
It's going to be interesting ....... at least for those of us that are tax nerds.